For me, Tohru and a time - traveler from an isekai or time - travel anime would be a great pairing. The time - traveler could introduce Tohru to different eras and cultures, and Tohru could show off her dragon powers in those new settings. Another good pair would be Kanna and a magical pet from a magical girl anime. They could get into all sorts of mischief together. And Kobayashi with a reclusive genius from a psychological anime. Kobayashi's down - to - earth nature could break through the genius's shell and they could form an unlikely friendship.
Pairing Tohru with a powerful mage from another anime like Gray from Fairy Tail would be really interesting. Their different powers and personalities would create a great dynamic. Another interesting pair could be Kanna with a cute and innocent character from a slice - of - life anime, like Azusa from K - On!. They could have some really funny and heartwarming interactions. And also, Kobayashi with a strict and no - nonsense character from a detective anime, like Conan from Detective Conan. Their contrasting personalities would lead to some interesting storylines.
One of the most interesting pairings could be Lucoa and a god - like character from an anime with a mythology - based setting, such as Amaterasu from Okami. The clash between a dragon and a god would be full of drama and intrigue. Then, there's Elma and a food - loving character from a cooking anime. They could have battles over food or collaborate to create the most amazing dishes. Also, Fafnir and a tech - savvy character from a mecha or sci - fi anime. The contrast between his traditional dragon ways and the high - tech world of the other character would make for an exciting story.